Error in Extension Manager logs when installing Blog on XWiki 17.10.3

Cannot load the owner document of [<spaces>
<cache>0</cache>
<classname/>
<customDisplay/>
<disabled>0</disabled>
<displayType>checkbox</displayType>
<idField/>
<multiSelect>1</multiSelect>
<name>spaces</name>
<number>4</number>
<picker>0</picker>
<prettyName>spaces</prettyName>
<relationalStorage>0</relationalStorage>
<separator>,</separator>
<separators>,</separators>
<size>10</size>
<sort>none</sort>
<sql>select distinct doc.web from XWikiDocument doc order by doc.web</sql>
<unmodifiable>0</unmodifiable>
<validationMessage/>
<validationRegExp/>
<valueField/>
<classType>com.xpn.xwiki.objects.classes.DBListClass</classType>
</spaces>] with reference []. Falling back on empty database list values.